Malanicheva T.G. — D. Med. Sc., Professor of the Department of propaedeutics of childhood diseases, and departmental pediatrics with the course of childhood diseases of the department of general medicine, tel. (843) 268-58-21, e-mail: [email protected]

Agafonova E.V. — Cand. Med. Sc., Assistant of the Department of propaedeutics of childhood diseases, and departmental pediatrics with the course of childhood diseases of the department of general medicine, tel. (843) 268-58-21, e-mail: [email protected]

The state of mucosal immunity in 53 children aged 3 to 7 years with community-acquired pneumonia (CAP) occurring against a background of recurrent respiratory diseases is examined. The main group constitutesof 30 children with community-acquired pneumonia, occurring against a background of recurrent respiratory diseases, the comparison group — 23 children with community-acquired pneumonia who do not belong to a group of frequently ill children, the control group — 25 children without acute respiratory diseases. Mucosal immunity is studied by evaluating the cellular composition of induced sputum, cytomorphological cell profile, functional activity of neutrophils of induced sputum, and some parameters of the cytokine status (IL-8, IL-10, TNF-α, IFN-γ). It was revealed that in case ofcommunity-acquired pneumoniaagainst a background of recurrent infectionsviolation of cytokine balance (decreased IL-8, IFNγ and increased TNF-α) leads to restriction of the output of neutrophil population in bronchial contents and alveolar secret and to increase of the number of neutrophils and epithelial cells with pronounced destructive changes of nuclei and cytoplasm. Secondary dysfunctions of mucosal immunity against a background of redistribution, morphocytological changes in cell populations and the formation of a neutrophil phenotype with low phagocytic capacity, requiring differentiated correction, are being developed.